Zoology
The two strands of DNA are:
A.
Antiparallel and complimentary
B.
Basically different in molecular arrangement
C.
Parallel and complimentary
D.
None of these
In a cell of E.coli, an operator gene combines with:
A.
Inducer gene to initiate structural gene transcription
B.
Inducer gene to terminate structural gene transcription
C.
Regulator protein to terminate structural gene transcription
D.
Regulator protein to initiate structural gene transcription
The diameter of DNA molecule is:
A.
50 Å
B.
20 Å
C.
100 Å
D.
200 Å
Which of the following process can be said as reversible to prophase?
A.
Anaphase
B.
Telophase
C.
Metaphase
D.
Interphase
A DNA strand directly synthesize the following except:
A.
Another DNA strand
B.
m-RNA
C.
Protein molecule
D.
t-RNA
In the operon concept, the regulator gene regulates chemical reaction in the cell by:
A.
Inhibiting transcription of mRNA
B.
Inactivating enzymes in the reaction
C.
Inactivating the substance in the reaction
D.
Inhibiting the migration of mRNA into cytoplasm
A triplet would code for a given amino acid as long as:
A.
The three bases are present in a particular sequence
B.
The first two bases are the same and have the same sequence
C.
The second and third bases are the same and have the same sequence
D.
None of these
Nucleic acid are the polymers of:
A.
Globulins
B.
Nucleoprotein
C.
Nucleoside
D.
Nucleotide
Mitosis results in:
A.
Reduction in the number of chromosomes
B.
Duplication of chromosomes
C.
Increase in the cell volume
D.
No change in number of chromosomes
Nuclear membrane disappear during mitosis at:
A.
Anaphase
B.
Telophase
C.
Early prophase
D.
Late prophase
Which one of the following is normally not present during replication of DNA?
A.
Exonuclease
B.
Endonuclease
C.
Ligase
D.
DNA polymerase
The chromosomes except those relating to sex, are known as:
A.
Heterosomes
B.
Autosomes
C.
Cytosomes
D.
Allosomes
First meiotic division during oogenesis occurs in:
A.
Secondary oocyte
B.
Primary oocyte
C.
First polar body
D.
Second polar body
Chromosomes do not occur in pairs in:
A.
Body cells
B.
Zygotes
C.
Gametes
D.
Germ cells
Sigma factor is a part of:
A.
INA polymerase
B.
RNA polymerase
C.
Nucleosome
D.
Ribosome
During translation the codon AUG codes for the amino acid:
A.
Leucine
B.
Arginine
C.
Methionine
D.
Glutamic acid
Each chromonema is made up of two fibrils, called sub-chromonemata, each with in diameter:
A.
50 Å
B.
150 Å
C.
200 Å
D.
350 Å
Which one of the following is the correct sequence of genes within an operon?
A.
Regulator, promotor, operator, structural
B.
Regulator, operator, Promotor, structural
C.
Structural, operator, regulator, promotor
D.
Promotor, operator, structural, regulator
The attachment point of two chromatids of a chromosome is known as:
A.
Kinetochore
B.
Primary constriction
C.
Secondary contriction
D.
None of these
During meiosis the pairing between homologous (polytene) chromosomes is:
A.
Interband to Interband
B.
Band to Band
C.
Puffs to Puffs
D.
Rings to Rings
Wobble pairing takes place:
A.
Under unusual condition, between homologous chromosomes of a somatic cell causing somatic crossing over
B.
In some cases between the third base of a codon and that of an anticodon
C.
In those rare instance where unequal crossing over takes place for the lack of segment pairing
D.
In radiation - induced base deletion from one strand of a DNA molecule so that the complementary counterpart of the other strand exhibits mispairing
Duplication of chromosomes without division of the nucleus resulting in an number of chromosomes within the cell is referred to as:
A.
Endomitosis
B.
Amitosis
C.
Mitosis
D.
Polyploidy
The inactive molecules of tRNA lack:
A.
C-C-A base sequence
B.
Anticodon arm
C.
Some of the nucleotides
D.
Phosphodiester backbone
RNA splicing is:
A.
Splitting of RNA molecule during transcription
B.
Cutting down of unwanted part from newly transcribed RNA
C.
Union of some additional nucleotides in the mRNA
D.
Rearrangement of nucleotides in tRNA
During transcription, the sequence of bases on mRNA is determined by:
A.
Template DNA
B.
Template RNA
C.
Both (a) and (b)
D.
Template proteins